Generally, gas burners are constituted such that the combustible gas introduced a gas supply nozzle and the air introduced through an air duct are mixed together in a mixing room of the burner, and the mixed air-gas is spouted through a plurality of flame holes formed at upper positions of the burner, thus flames being produced by igniting the spouting air-gas mixture.
However, in such conventional gas burners, the mixing room takes the form of a tube, and therefore, the gas pressure spouting through the flame hole becomes very low. Therefore, this brings the result that the air-gas mixing ratio becomes very low, or oxygen deficiency is caused. This in turn causes incomplete combustions at the flame hole, and such incomplete combustions remain indefinitely without being extinguished.
Such incomplete combustions can pollute the room air due to the incompletely burnt exhaustion gas, and especially, in the case where a gas boiler is installed in the rest room to supply hot water to the bath room, an oxygen depletion and a suffocating accident can occur due to the fact that the oxygen in the room is continuously consumed by the burner of the boiler.